Numerical Study on the Low Pressure Die Casting of AZ91D Wheel Hub

Abstract:

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Most magnesium alloy components available for automobile are made through die casting. In this paper, PAM-CASTTM, commercial die casting simulation software based on the finite difference method, is employed to simulate the low-pressure die casting process of magnesium wheel hub. The temperature field and velocity field during filling and solidification stages are analyzed; the evolution of temperature distribution and liquid fraction was numerically studied. Then, the potential
defects including the gas entrapments in the middle of the spokes, shrinkages between the rim and the spokes are predicted. The cooling performance of mould during casting is also investigated. Via analyzing the shrinkage defects generated under various cooling conditions, the cooling system set in the side mould is found to be more effective for enhancing the cooling capacity at the rim/spoke junction areas. With this cooling system, the hot spots at the junctions are obviously reduced and
product quality is improved.

Abstract: The technology of computer numerical simulation on casting process is an important
frontal field of material science and technology. The numerical simulations of camera shell in the
pressure die casting process were carried out. The distributions of temperature and solidification time
in the filling process were obtained. Based on the simulated results and the Niyama criterion G/ R ,
the positions of slack were predicted, which were agreement with the practical result. Consequently,
an improved scheme was presented, in which the workpiece defects were obviously reduced. So it’s
significant for the application of numerical simulation on improving the quality of the casting,
shortening the period of producing, reducing the cost and guiding the engineer for taking reasonable
method to optimize the technological design.

Abstract: In this study, numerical analysis applying the finite element method (FEM) was used to
investigate the effect of heat flux and temperature on thermal strain of aluminum alloy casting mold.
For numerical analysis, analysis model was considered the effect of shrinkage, rapid temperature
variation on the casting mold and was applied the temperature calibration to reduce the deformation
and stress by temperature difference of inside and outside the mold during the cooling process. In
detail, temperature, deformation and stress distributions occurred inside of casting mold predicted by
numerical method and then investigated the correlations between the heat flux and temperature
variation during the cooling process. As a result, aluminum alloy casting mold is occurred
deformation and stress because of rapid temperature difference in the initial of cooling, but it can be
reduced the thermal strain through the heat flux control and temperature calibration. Accordingly, the
technique of this numerical study will be helped to make the effective and the good quality of casting
mold products.

Abstract: The nonferrous alloy castings will be much demanded with the development of aerospace, light-weight weapons and automotive industry. Casting CAD/CAE technology has played an increasingly important role in foundry. It can help technician to design casting process and simulate heat transferring and molten metal flowing before actual production. Firstly, the main contents and basic principles, mathematical models of casting CAD and CAE were introduced. Secondly, the casting CAD/CAE technology route was interpreted, and then several CAD/CAE applications of casting process design and simulating were carried out on nonferrous alloys, such as aluminum, magnesium and copper. The results indicate that CAD/CAE technology can be applied to casting process design and predict casting defects which usually occur during the casting mold filling and solidification process, it can provide references to optimize casting process, so as to improve casting quality, reduce the rejection rate and shorten the development cycle of new products.

Abstract: The numerical simulations of mold filling and solidification process for the A380 aluminum alloy were done by the supposed mathematical model. The casting defects in the process of mold filling and solidification were predicted by the result of the casting simulation. The casting defects of simulation are well compared with the practice. Some measures presented were improved for the existing technological process.

Abstract: Filling and solidification for aluminum alloy packing block in die casting were simulated by numerical simulation. Distribution and change of temperature field as well as velocity field were visualized. The desirable processing parameters can be obtained with pouring temperature of 620°C and mould temperature of 180°C as well as shot velocity of 4m/s. The qualified products were obtained on the basis of the optimized die-casting parameters.